1. Field of the Invention
The present invention relates to the field of display, and in particular to an active matrix organic light emitting diode (OLED) display (AMOLED) device and driving method thereof.
2. The Related Arts
The organic light-emitting diode (OLED) display has the advantages of active light-emitting, low driving voltage, high luminance efficiency, short response time, high clarity and contrast, near 180°, large working temperature range, and ability to realize flexible display and large-area full-color display, and therefore is common considered as the most promising display.
Based on the driving method, OLED display can be categorized as passive matrix OLED display (PMOLED), or active matrix OLED display (AMOLED); that is, the direct addressing and thin film transistor (TFT) addressing, wherein the AMOLED display panel is thin, light-weighted, active light-emitting, quick response, wide viewing angle, rich color, high luminance, low energy-consumption, and is often considered as the third generation display technology after the liquid crystal display (LCD). AMOLED can be used to realize large-size, high-definition panel, and is the future of the display technology.
In the known OLED display device, a pixel comprises a red sub-pixel R, a green sub-pixel G and a blue sub-pixel B. As the user demands grow, a four-color display panel is developed. In the four-color display panel, a pixel comprises a red sub-pixel, a green sub-pixel, a blue sub-pixel and a white sub-pixel. Compared to the conventional three-color display panel, the additional white sub-pixel can improve the opening ratio and the color expressiveness of the display panel. As shown in FIG. 1, each pixel comprises a red sub-pixel R, a green sub-pixel G, a blue sub-pixel B, and a white sub-pixel W. The sub-pixels are arranged in an array form, wherein each column of sub-pixels has the same layout order as the adjacent column of sub-pixels, and the sub-pixels in each row are of the same color. Each row of sub-pixels inputs a Gamma curve of corresponding color. In other words, the first row of sub-pixels uses red Gamma curve Red_Gamma, the second row of sub-pixels uses green Gamma curve Green_Gamma, the third row of sub-pixels uses blue Gamma curve Blue_Gamma, and the fourth row of sub-pixels uses white Gamma curve White_Gamma. As such, the layout structure of the pixels is simpler, but not necessary provides the optimal display effect.
As the technology progresses, as shown in FIG. 2 and FIG. 3, a pixel structure of interleaved form arrangement is developed. In the interleaved form arrangement, the vertically adjacent two sub-pixels in the same row of pixel are of different color; therefore, the conventional Gamma curve input cannot be used to drive the display panel.